G. Duchén Sánchez, B. del Muro Cuellar, J. F. Marquez Rubio, M. Velasco Villa, and M. A. Hernández Pérez, “Observer-Based PD Controller for a Class of High Order Linear Unstable Delayed Systems”, IEEE LAT AM T, vol. 20, no. 2, pp. 291–300, Sep. 2021.